A pragmatic continuum level model for the prediction of the onset of keyholing in laser powder bed fusion

Philo, AM, Mehraban, S, Holmes, M, Sillars, S, Sutcliffe, CJ, Sienz, J, Brown, SGR and Lavery, NP
(2019) A pragmatic continuum level model for the prediction of the onset of keyholing in laser powder bed fusion. INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY, 101 (1-4). pp. 697-714.

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Laser powder bed fusion (L-PBF) is a complex process involving a range of multi-scale and multi-physical phenomena. There has been much research involved in creating numerical models of this process using both high and low fidelity modelling approaches where various approximations are made. Generally, to model single lines within the process to predict melt pool geometry and mode, high fidelity computationally intensive models are used which, for industrial purposes, may not be suitable. The model proposed in this work uses a pragmatic continuum level methodology with an ablation limiting approach at the mesoscale coupled with measured thermophysical properties. This model is compared with single line experiments over a range of input parameters using a modulated yttrium fibre laser with varying power and line speeds for a fixed powder layer thickness. A good trend is found between the predicted and measured width and depth of the tracks for 316L stainless steel where the transition into keyhole mode welds was predicted within 13% of experiments. The work presented highlights that pragmatic reduced physics-based modelling can accurately capture weld geometry which could be applied to more practical based uses in the L-PBF process.

Item Type: Article
Uncontrolled Keywords: Additive manufacturing, Laser powder bed fusion, Modelling, Keyhole-mode laser melting, 316L stainless steel
Depositing User: Symplectic Admin
Date Deposited: 20 May 2020 10:27
Last Modified: 18 Jan 2023 23:51
DOI: 10.1007/s00170-018-2770-7
Open Access URL: https://link.springer.com/article/10.1007/s00170-0...
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URI: https://livrepository.liverpool.ac.uk/id/eprint/3088159